Firefighters had been battling the flames with water and a fire retardant, but were staying at least 1,000 ft from the burning tankers for fear of more blasts, Mr Lauzon told reporters earlier on Sunday.

"We lost the bibliotheque [library] which had all the memories of people here - it's a mess," said Mr Lauzon.

People whose homes have been badly damaged were being given shelter at a nearby school.

The Montreal, Maine & Atlantic train had been parked in the village of Nantes - about 7km (four miles) from Lac-Megantic - during an overnight driver shift-change, said a company spokesman.

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Media captionEyewitnesses say the streets "were filled with fire"

Its 73 cars carrying pressurised containers of crude oil somehow became uncoupled from five locomotive engines, gathering speed as they rolled downhill before derailing in the heart of Lac-Megantic.

Bernard Demers, who runs a restaurant near the blast site, said the fireball that followed the derailment at around 01:00 (05:00 GMT) on Saturday was "like an atomic bomb", the Sunday Telegraph reported.

The train had been travelling from the Bakken Field in North Dakota to a refinery in Saint John, New Brunswick.